3 * File name: ir/ir/irgopt.h
4 * Purpose: Optimizations for a whole ir graph, i.e., a procedure.
5 * Author: Christian Schaefer, Goetz Lindenmaier
6 * Modified by: Sebastian Felis
9 * Copyright: (c) 1998-2003 Universität Karlsruhe
10 * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
16 * Optimizations for a whole ir graph, i.e., a procedure.
18 * @author Christian Schaefer, Goetz Lindenmaier
26 /** Applies local optimizations (see iropt.h) to all nodes reachable from node n.
28 * @param n The node to be optimized.
30 void local_optimize_node(ir_node *n);
32 /** Applies local optimizations (see iropt.h) to all nodes in the graph.
34 * @param irg The graph to be optimized.
36 * After applying local_optimize_graph() to a IR-graph, Bad nodes
37 * only occure as predecessor of Block and Phi nodes.
39 void local_optimize_graph (ir_graph *irg);
41 /** Applies local optimizations (see iropt.h) to all nodes in the graph.
43 * @param irg The graph to be optimized.
45 * After applying local_optimize_graph() to a IR-graph, Bad nodes
46 * only occure as predecessor of Block and Phi nodes.
48 * This version used a fixpoint iteration.
50 void optimize_graph_df(ir_graph *irg);
52 /** Performs dead node elimination by copying the ir graph to a new obstack.
54 * The major intention of this pass is to free memory occupied by
55 * dead nodes and outdated analyzes information. Further this
56 * function removes Bad predecessors from Blocks and the corresponding
57 * inputs to Phi nodes. This opens optimization potential for other
58 * optimizations. Further this phase reduces dead Block<->Jmp
59 * self-cycles to Bad nodes.
61 * Dead_node_elimination is only performed if options `optimize' and
62 * `opt_dead_node_elimination' are set. The graph may
63 * not be in state phase_building. The outs datasturcture is freed,
64 * the outs state set to outs_none. Backedge information is conserved.
65 * Removes old attributes of nodes. Sets link field to NULL.
66 * Callee information must be freed (irg_callee_info_none).
68 * @param irg The graph to be optimized.
70 void dead_node_elimination(ir_graph *irg);
72 typedef struct _survive_dce_t survive_dce_t;
75 * Make a new Survive DCE environment.
77 survive_dce_t *new_survive_dce(void);
80 * Free a Survive DCE environment.
82 void free_survive_dce(survive_dce_t *sd);
85 * Register a node pointer to be patched upon DCE.
86 * When DCE occurs, the node pointer specified by @p place will be
87 * patched to the new address of the node it is pointing to.
89 * @param sd The Survive DCE environment.
90 * @param place The address of the node pointer.
92 void survive_dce_register_irn(survive_dce_t *sd, ir_node **place);
94 /** Cleans the control flow from Bad predecessors.
96 * Removes Bad predecessors from Blocks and the corresponding
97 * inputs to Phi nodes as in dead_node_elimination but without
100 * Conserves loop information.
102 * @param irg The graph to be optimized.
104 void remove_bad_predecessors(ir_graph *irg);
106 /** Inlines a method at the given call site.
108 * Removes the call node and splits the basic block the call node
109 * belongs to. Inserts a copy of the called graph between these nodes.
110 * Assumes that call is a Call node in current_ir_graph and that
111 * the type in the Call nodes type attribute is the same as the
112 * type of the called graph.
113 * Further it assumes that all Phi nodes in a block of current_ir_graph
114 * are assembled in a "link" list in the link field of the corresponding
115 * block nodes. Further assumes that all Proj nodes are in a "link" list
116 * in the nodes producing the tuple. (This is only an optical feature
117 * for the graph.) Conserves this feature for the old
118 * nodes of the graph. This precondition can be established by a call to
119 * collect_phisprojs(), see irgmod.h.
120 * As dead_node_elimination this function reduces dead Block<->Jmp
121 * self-cycles to Bad nodes.
123 * Called_graph must be unequal to current_ir_graph. Will not inline
125 * Sets visited masterflag in current_ir_graph to the max of the flag in
126 * current and called graph.
127 * Assumes that both, the called and the calling graph are in state
128 * "op_pin_state_pinned".
129 * It is recommended to call local_optimize_graph() after inlining as this
130 * function leaves a set of obscure Tuple nodes, e.g. a Proj-Tuple-Jmp
131 * combination as control flow operation.
133 * @param call the call node that should be inlined
134 * @param called_graph the IR-graph that is called at call
136 * @return zero if method could not be inlined (recursion for instance),
137 * non-zero if all went ok
139 int inline_method(ir_node *call, ir_graph *called_graph);
141 /** Inlines all small methods at call sites where the called address comes
142 * from a SymConst node that references the entity representing the called
145 * The size argument is a rough measure for the code size of the method:
146 * Methods where the obstack containing the firm graph is smaller than
147 * size are inlined. Further only a limited number of calls are inlined.
148 * If the method contains more than 1024 inlineable calls none will be
150 * Inlining is only performed if flags `optimize' and `inlineing' are set.
151 * The graph may not be in state phase_building.
152 * It is recommended to call local_optimize_graph() after inlining as this
153 * function leaves a set of obscure Tuple nodes, e.g. a Proj-Tuple-Jmp
154 * combination as control flow operation.
156 void inline_small_irgs(ir_graph *irg, int size);
159 /** Inlineing with a different heuristic than inline_small_irgs().
161 * Inlines leave functions. If inlinening creates new leave
162 * function inlines these, too. (If g calls f, and f calls leave h,
163 * h is first inlined in f and then f in g.)
165 * Then inlines all small functions (this is not recursive).
167 * For a heuristic this inlineing uses firm node counts. It does
168 * not count auxiliary nodes as Proj, Tuple, End, Start, Id, Sync.
170 * @param maxsize Do not inline any calls if a method has more than
171 * maxsize firm nodes. It may reach this limit by
173 * @param leavesize Inline leave functions if they have less than leavesize
175 * @param size Inline all function smaller than size.
177 void inline_leave_functions(int maxsize, int leavesize, int size);
181 * Pins all floating nodes to a block where they
182 * will be executed only if needed. Depends on the flag opt_global_cse.
183 * Graph may not be in phase_building. Does not schedule control dead
184 * code. Uses dominator information which it computes if the irg is not
185 * in state dom_consistent. Destroys the out information as it moves nodes
186 * to other blocks. Optimizes Tuples in Control edges.
187 * @todo This is not tested!
189 * Call remove_critical_cf_edges() before place_code(). This normalizes
190 * the control flow graph so that for all operations a basic block exists
191 * where they can be optimally placed.
193 * @todo A more powerful code placement would move operations past Phi nodes
196 void place_code(ir_graph *irg);
198 /** Places an empty basic block on critical control flow edges thereby
201 * A critical control flow edge is an edge from a block with several
202 * control exits to a block with several control entries (See Muchnic
205 * @param irg IR Graph
207 void remove_critical_cf_edges(ir_graph *irg);
209 # endif /* _IRGOPT_H_ */